1. Technical Field
The present invention relates to integrated circuits, and more particularly to via structures and methods of their fabrication.
2. Description of the Related Art
Three-dimensional integration (3Di) is an emerging technology that enables the manufacture of vertically stacked integrated systems and functional components, such as processors, memory, sensors, etc. There are many advantages of such an integration approach, including, among other benefits, a small form factor, simplified heterogeneous integration and multifunctional designs, reduced packaging, lower power consumption, lower cost and shorter design-to-market times.
In typical 3Di schemes, the vertical integration of two different systems including functional components, such as chips, packages, wafers, etc., is performed by bonding the two systems to each other and then defining and creating vias filled with electrically conductive material in a massively parallel fashion in order to establish a reliable electrical connection between the aligned functional components of the two systems, as needed. This electrical interconnection can be achieved by forming through-silicon via (TSV) structures. Here, for each pair of vertically aligned functional components, two vias are defined from the top of the bonded systems structure. This is done so that one via lands on a predefined landing pad on the first/top component and another via lands on a predefined landing pad on the second/bottom component. Subsequently, an electrical connection strap is defined, as needed, in order to connect the two vias and thereby connect the two functional components.